Radical-assisted sequential CVD

1. A method for depositing a metal oxide on a substrate surface in a deposition chamber, comprising steps of: (a) depositing a monolayer of metal on the substrate surface by flowing a metal molecular precursor gas or vapor bearing the metal over a surface of the substrate, the surface saturated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface covered with ligands from the metal precursor and therefore not further reactive with the precursor; (b) terminating flow of the precursor gas or vapor; (c) purging the precursor with inert gas; (d) flowing a first radical species into the chamber and over the surface, the radical species highly reactive with the reaction product and combining with the reaction product to create volatile species and saturate the surface with the first radical species; (e) flowing radical oxygen into the chamber to combine with the metal monolayer deposited in step (a), forming an oxide of the metal; (f) flowing a third radical species into the chamber terminating the surface with the first reactive species in preparation for a next metal deposition step; and (g) repeating the steps in order until a composite film of desired thickness results.

2. The method of claim 1 wherein the first and third radical species are both atomic hydrogen, and the metal surface in step (f) is terminated with hydroxyl species reactive with the metal precursor to deposit the metal.

3. The method of claim 2 wherein the oxygen and hydrogen atomic steps (e) and (f) are repeated to improve film quality.

4. The method of claim 1 wherein steps (e) and (f) are combined into one step wherein the surface is reacted with hydrogen and oxygen atoms simultaneously.

5. The method of claim 1 wherein the metal precursor is tantalum pentachloride and the film is tantalum pentoxide.

6. The method of claim 1 wherein the metal precursor is trimethylaluminum or aluminum trichloride and the film is aluminum oxide.

7. The method of claim 1 wherein the metal precursor is titanium tetrachloride or titanium tetraiodide and the film is titanium oxide.

8. The method of claim 1 wherein the metal precursor is niobium pentachloride and the film is niobium pentoxide.

9. The method of claim 1 wherein the metal precursor is zirconium tetrachloride and the film is zirconium oxide.

10. The method of claim 1 wherein the metal precursor is hafnium tetrachloride and the film is hafnium oxide.

11. The method of claim 1 wherein the metal precursor is zinc dichloride and the film is zinc oxide.

12. The method of claim 1 wherein the metal precursor is molybdenum hexafluoride or molybdenum pentachloride and the film is molybdenum oxide.

13. The method of claim 1 wherein the metal precursor is manganese dichloride and the film is manganese oxide.

14. The method of claim 1 wherein the metal precursor is tin tetrachloride and the film is tin oxide.

15. The method of claim 1 wherein the metal precursor is indium trichloride or trimethylindium and the film is indium oxide.

16. The method of claim 1 wherein the metal precursor is tungsten hexafluoride and the film is tungsten oxide.

17. The method of claim 1 wherein the metal precursor is silicon tetrachloride and the film is silicon dioxide.

18. The method of claim 1 wherein the first radical species is atomic hydrogen and steps (e) and (f) are united to one step using OH radicals, and the metal surface in step (t) is terminated with hydroxyl species reactive with the metal precursor to deposit the metal.

19. A method for depositing a metal nitride on a substrate surface in a deposition chamber, comprising steps of: (a) depositing a monolayer of metal on the substrate surface by flowing a metal precursor gas or vapor bearing the metal over a surface of the substrate, the surface saturated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface covered with ligands from the metal precursor and therefore not further reactive with the precursor; (b) terminating flow of the precursor gas or vapor; (c) purging the precursor with inert gas; (d) flowing a first radical species into the chamber and over the surface, the radical species highly reactive with the surface ligands of the metal precursor layer and eliminating the ligands as reaction product and also saturating the surface; (e) flowing radical nitrogen into the chamber to combine with the metal monolayer deposited in step (a), forming a nitride of the metal; (f) flowing a third radical species into the chamber terminating the surface with the first reactive species in preparation for a next metal deposition step; and (g) repeating the steps in order until a composite film of desired thickness results.

20. The method of claim 19 wherein the first and third atomic radical species are both atomic hydrogen, and the metal surface in step (f) is terminated with amine species reactive with the metal precursor to deposit the metal.

21. The method of claim 20 wherein steps (e) and (f) are combined to one step wherein the surface is reacted with hydrogen and nitrogen atoms simultaneously.

22. The method of claim 19 wherein the metal precursor is tungsten hexafluoride and the film is tungsten nitride.

23. The method of claim 19 wherein the metal precursor is tantalum pentachloride and the film is tantalum nitride.

24. The method of claim 19 wherein the metal precursor is aluminum trichloride or trimethylaluminum and the film is aluminum nitride.

25. The method of claim 19 wherein the metal precursor is titanium tetrachloride and the film is titanium nitride.

26. The method of claim 19 wherein the metal precursor is silicon tetrachloride or dichlorosilane and the film is silicon nitride.

27. The method of claim 19 wherein the metal precursor is trimethylgallium and the film is gallium nitride.

28. The method of claim 19 wherein the first radical species are atomic hydrogen and steps (e) and (f) are united to one step using one or both of NH and NH.sub.2 radicals, and the metal surface in step (f) is terminated with amine species reactive with the metal precursor to deposit the metal.

29. A process for building a metal, metal oxide, or metal nitride film on a substrate surface, wherein deposition steps comprising flowing a metal precursor gas or vapor over the surface with the surface terminated with a hydroxyl species reactive with the metal precursor to deposit the metal, are alternated with steps comprising flowing atomic radical hydrogen, oxygen and hydrogen again, thereby volatilizing products remaining from the metal deposition chemistry, oxidizing the metal monolayer, then terminating the metal surface with hydroxyl species again in preparation for a next deposition reaction.

30. A method for depositing a compound film on a substrate surface in a deposition chamber, comprising steps of: (a) depositing a monolayer of metal on the substrate surface by flowing a metal molecular precursor gas or vapor bearing the metal over a surface of the substrate, the surface saturated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface covered with ligands from the metal precursor and therefore not further reactive with the precursor; (b) terminating flow of the precursor gas or vapor; (c) purging the precursor with inert gas; (d) flowing a first radical species into the chamber and over the surface, the radical species highly reactive with the reaction product and combining with the reaction product to create volatile species and saturate the surface with the first radical species; (e) flowing nonmetal radical species into the chamber to combine with the metal monolayer deposited in step (a), forming a compound film of the metal; (f) flowing a third radical species into the chamber terminating the surface with the first reactive species in preparation for a next metal deposition step; and (g) repeating the steps in order until a composite film of desired thickness results.

31. The method of claim 30 wherein the first and third radical species are both atomic hydrogen, and the metal surface in step (f) is terminated with hydride species of the nonmetallic element that are reactive with the metal precursor to deposit the metal.

32. The method of claim 30 wherein the non-metallic and hydrogen atomic steps (e) and (f) are repeated to improve the film quality.

33. The method of claim 30 wherein steps (e) and (f) are combined into one step wherein the surface is reacted with hydrogen and non-metallic atoms simultaneously.

34. The method of claim 30 wherein the metal precursor is molybdenum hexafluoride or molybdenum pentachloride, the non metallic element is sulfur and the film is molybdenum disulfide.

35. The method of claim 30 wherein the metal precursor is zinc dichloride, the non metallic element is sulfur and the film is zinc sulfide.